Ok, I’m at a loss. I was at the track, NCBike, came out of turn 1 and the bike just died. Got it back to the pits and it wouldn’t start. Tried again to start it at which point it started up, but it made the most horrific sound like I had marbles or something bouncing around inside the cylinder. I’ve ruled that out at this point as I now have entire tore apart. I thought at some point I’d come across some obviously broken bits, but nothing. I’m at a loss and hoping someone has seem/ heard this before. So... who’s got ideas?

You say the engine is torn apart, but you haven't found a problem? That doesn't compute. It is clear that you have not taken the motor apart. Your problem could be anything, but whatever it is, it has caused particulate contamination, which must be thoroughly cleaned. So in order to do this, the motor mast be totally disassembled. there is no short cut. No wild assed guess from the forum can eliminate that.

Vdub, I didn't find any signs of piston slap and the noise that I thought sounded like marbles or something bouncing around in the engine was very erratic. I thought for sure I broke a valve, but not the case. At any rate, pistons don't show any sign and neither does the cylinder. I haven't found any bad bearings either, but I'll be going back over it again today to see if I missed something.

So far the only things I have found have been the valve lash is on the low side of things:

Intakes .006 .006 .005 .006 Exhaust .009 .010 .010 .009

And I have a small abnormal wear mark on on or the cam lobes, but it's not enough to be causing this and there's no damage/wear on the cam follower.

Aside from that, I did break the clutch hub getting it off, luckily I have a spare.

Stevel, don't troll me. I asked the question here because the people on BadWeb are generally solid and this is the central repository for knowledge on these bikes. I figured if anyone had run into a similar symptom, they might be on here.

If all you can bring to the conversation is,"It is clear you have not taken the motor apart." when you don't know me, then go back under your bridge and wait for someone else to troll.

I'm reaching here but maybe momentary oil pressure loss from cavitation? How do the main bearings look? And can we see a pic of the cam lobe wear? I haven't seen it in person but these engines are known to have occasional cam lobe wear issues.

From what the noise you describe the cam has a big chunk missing but is more than likely a bearing maybe clutch basket or a main .can you show a better pic of the cylinder and pistons ..are the rods free moving or do thay stick a littel when rotating .

was the nut loose on the right side of the crank? I heard the clatter but didn't catch it intime on my 1125 and it un-threaded and cracked the clutch side engine cover. but I don't think that would cause running issues too... could it be 2 separate issues? were there any other circumstances/conditions that'd cause a clatter? I know my XBs sound like they are gonna grenade (because of gear teeth slapping/drivetrain lash) if they are idling in gear on the paddock stands

I rode NC bike once with TPM. fun track and great to work on the basics/refine technique

I agree with Tick, the noise you describe makes me think Mechanical. Bearing. Slap. But, that exhaust cam is toast. The only issue I have with that being the problem is that I feel like you described an irregular noise. The cam would be consistent.

Chopped_burban, My apologies. You certainly did take the motor apart. You are correct, I don't know you. I based my reply on the myriad of queries on this forum from people that provide symptoms, no test results and yet expect us to be mind readers.

Your symptoms indicate that something is loose. It is extremely rare that at disassembly that looseness is not immediately revealed, hence my comments.

If you approach the problem holistically, you either lost fuel or spark at turn 1. Initially the engine did not start in the pits, but when it did, you heard the marbles in the engine. Assuming an engine fault, you disassembled the motor, yet you have found no fault. It is very conceivable that the fault was a fuel pressure issue. Poor fueling can cause erratic ignition and detonation and often does sound like marbles in the motor. I would suspect a fuel pump issue, at least enough to thoroughly test the pump. Correct fuel pressure is critical to the correct operation of a fuel injected engine, so much so that a fuel pressure gauge should be a separate instrument right in front of your face at all times, not just a selection when in diagnostic mode.

trouble shooting at the track is hard...trouble shooting over the internet is harder... 1) check your "balance gears" some early '08s had incorrect heat treatment...here's a pix of mine:

2) like Steve suggested ...either fuel or timing could cause pre-ignition/detonation symptoms (Marbles in my cylinders) 2a) metal fragments from the balance gear or from the sprag clutch could have interfered with the timing wheel signal to the crank position sensor...I would check both for debris 2b) crank position sensor wires/connections...it's not in the cleanest area 3) fuel pump "feed thru" connector has a history of going bad...the wires and external connection look fine, but that "hidden" connection at the "bulkhead" where the wires enter the tank have been reported to fail...poor fuel delivery = lean condition= pre-ign/detonation. 4) Vacuum leak...the bike has a "vacuum" operated "slipper" clutch...the big diaphragm has got to seal in the assembly stack up of the clutch cover/slave cylinder housing 5) back in the day some Suzuki big twins ( TL series) would back fire and blow the throttle bodies out of their mounts...if you didn't know what to look for the bike would run but continue to back fire and high idle. (vacuum leak) 6) WASG - the wheel bearing or the belt tension bearings grenade-ed - sounds like breaking glass/bouncing marbles in a can 7) suggest you post a question on the racing area of this forum ...some of the racers ( like Rodrob or Dean could help.) good luck ...hth

Tick, pics are coming. Bearings all appear to be fine. I'll be checking clearances on all of them before they go back together, but they feel smooth.

Nillaice, as far as the nut you asked about, and any other for that matter, they were all solid.

Vdub, my thoughts match up with yours about the random vs. consistent noise coming off the valve train.

Steve, thanks. Fuel pump will be my next item to check. Not sure how much I can assess before the engine is back in the frame, but it will at least get pulled and get a visual inspection. I'm trying to piece together the needed fittings. Tried shopping around for a set with appropriate fittings and came up short. Also will keep in mind spark, plugs, coils.

At this point, almost seems like everything except what's in the case is suspect.

Nuts, geez. I looked... my gears all still look as the should. Everything will be thoroughly cleaned before reassembly, although on inspection, didn't find anything I would think would interfere. Either way, it will be clean. I'll check out the vacuum leak also. I didn't notice anything, but it's an easy enough thing to check. Your WASG probably not... was making the noise when the bike was stationary... those parts weren't in play at the time.

Well, thanks for all the input. I don't have a lot of time to work on it this week, but by the end of the weekend, I should have something to report back.

First cylinder was the rear, second picture is the front cylinder. Only a little bit of scuffing on the front and back wall of the cylinder.

Next two are a couple shots of the pistons. Nothing I could pick out as an issue here either. Crank spins freely. I'll likely pop the caps and measure those as well before putting it all back together.

Is it possible to post an audio link of the noise? I've always thought these bike's sound like a bag of rocks in a can to begin with. If you have some video or audio, would probably help too. Btw, these pictures are absolutely amazing.

Well, at least I was able to swap out the exhaust cam before it became an issue. And I finally got around to getting the thermal barrier tape on the inside of the frame. That came out pretty nice if I do say so myself.

I have a few more things I want to get done on her over the winter, but I'll save that for future posts. Who knows, maybe I'll be able to document things going forward in a more instructional way rather than frustrated way. I do appreciate all the input and glad everyone liked the pics. Thank you.

Indeed all glass pack mufflers are not equal. I experienced the exact same problem in the 80s with an Opel, of all things. The cheap plain steel core had rusted and collapsed. Took forever to figure it out, as the engine started and idled OK, but died on opening the throttle. Didn't make any loose marble noises, but did have a strange hiss once you shut it down, like a tire losing air.

Kevin Cameron wrote of a similar problem in one of his Cycle magazine columns. After a 2-stroke holed a piston, he quickly rebuilt in time for the next day's race. Problem was, all that piston debris found a home in the silencer, unbeknownst to the hapless pit crew. That's what made me check the Opel's muffler, which was plugged solid.

On your Barker, I'm at a loss as to why there is a mesh cone in the muffler. Seems like a corrosion clog waiting to happen. Perhaps related to managing the exhaust system wave(s)?

In the 2010 exhaust shoot-out, the Barker did make good power, and was lighter than the RT-3 I was also considering. I preferred the more robust construction of the RT-3, even if it weighed a bit more. The inner core of the RT-3 is perforated stainless of a greater thickness than the photos of the dissected Barker. Although I know it's not always a valid predictor of an effective exhaust system, I do prefer a pipe I can see through that doesn't have any obvious lumps, ridges, or misaligned joints.

I had thought your clutch hub nut might have been just loose enough to allow some minor movement, but figured you would probably have noticed that during the autopsy.

There was a thread related to problems with the rotor nut working loose in under racing conditions, which apparently led to the call for an increased torque and the use of high heat high strength threadlocking compound being called for in the service manual.

Nice work on the thermal barrier. You did a much more comprehensive and aesthetic job on yours than I did on mine. Although I didn't have the engine out, I did take the time to cover the bottom of the airbox, and wormed some large sections onto the inner frame rails. I may just pull the frame off the engine when I do the valves at 12k miles and emulate your excellent work. Your effort should make a significant improvement in cooling and improved combustion efficiency.

Araignee, the cone is/was the quiet core. Barkers actually sells a 1" diameter and 1-1/2" quiet core. They did knock the noise down quite a bit but seemed to keep the deeper exhaust note.

Barkers sells the same two quiet cores for all of their on and off-road systems and does sell just the screen portion as a spark arrestor. Can only figure they are doing it as one configuration for everything.

What you said about the American Sportbike shootout is actually exactly how I picked mine. I just happen to decide on something quieter.

For now, the stock exhaust is back on and it's likely to stay that way at least until next spring. I don't mind the stock exhaust, it just doesn't fit with the full fairings. Not while maintaining the functional use of the belly pan. I know I can slice the back off. Since I still haven't gotten them painted and mounted, no rush. Winter maintenance season is coming.

Thanks for enlightening me on the Barkers quiet cores. I had thought they might have just used a smaller core diameter.

Check out aph-performance-engineering.com for their take on a modified stock system that is more compact and might fit with your fairing. I would think it is probably a bit quieter as well. They make extended exit cones that reduce some carbon fouling of the rear brake disk and wheel. I expect they have ECM mods to suit their products.

They also make some beautiful full systems in exotic materials, but they aren't cheap.

Dean Adams and others occasionally offer modified stock systems.

The RT-3 does have a punishing idle note, but it smoothes out once you're underway. I try to avoid antagonizing the locals and the gendarmes when I'm around either group.

I am also getting ready for winter upgrades, switching to a 3-bearing rear and new front in Villain Black, with Braking wave rotors and EBC HH pads. Haven't decided whether to sell the Piranha Black stock wheels, which have pricey ceramic hybrid bearings with about 3K on them, or keep them for spares.

Also planning to start doing my own tire changes and balancing. The tools and supplies pay off after changing 4 tires, considering the H-D dealer rate of $50 each for a loose wheel.

I hope you didn't tear down that motor for nothing. The 1125 motor is/was notorious for making lots of noise at idle. There was a video someone posted years ago of an 1125 with stock exhaust and then with an aftermarket pipe. The aftermarket pipe quieted the motors noise down considerably. I forget what pipe it was. This is my first login in years and I still have my '08 1125R...sold my '06 XB9SX though

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